A conventional belt conveyer as shown in FIG. 1 includes an endless belt B wound on a pair of rollers R for conveying purpose, on which the belt B will sag ("S") after being loaded by weight G of goods or person(s), causing unsmooth moving of the belt and uncomfortable standing or walking on such a sagging belt.
Even though a plurality of intermediate rollers R1 as shown in FIG. 2 may be provided in between the front and rear rollers R to prevent the sagging defect as aforementioned, the plural intermediate rollers R1 will form a corrugated surface C which still causes uncomfortable feeling when trodden by someone's foot thereon.
If a flat supporting surface S1 is located beneath the belt B as shown in FIG. 3, the corrugated surface as found in FIG. 2 will then be overcome. However, the load G on the belt B may cause a friction F between the belt B and the supporting surface S1, influencing or retarding the movement of the belt B.